5 votesDarcy Detlor commented
It is an interesting idea, but unfortunately not possible. These devices have internal serial numbers. Once you have a password for the device it can be reused indefinitely.
If we give you a password for both devices, then you can install on both. There is no way to disable a device, because all you have to do is hard boot it an it is brand new again.
Nothing will be stored on the device to prevent you from reusing the password again and reactivating the software.